You boys are full of good info. Unfortunately i have yet to find a solid number. What is a "solid" number HP-wise for a stock auto or a stock 6 speed? Trying to decide which to go with. Thanks boys ... i'll have you Colorado guys over for a beer when i get my truck just to piss of the neighbors.

:grd:
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I think it's around 65-85 hp before you want to look to upgrade the tranny. I'm not 100% on that I'm sure someone with more knowledge will chime in.

90 on the edge . dave

There was a good thread yesterday on this. The guys that REALLY know these tranny's recommend no more than 50 hp for the LLY. If you run more than this you will greatly reduce the life of your tranny.

I would not go with the 6 speed. I hate the fact that you get a detuned truck with a 6 speed. The 6 speed tranny will hold a lot, but the clutch is a bit to be desired. I have a 6 speed with a dual disc clutch and I have an allison ordered. It cost a little more to upgrade the ally, but worth the money. Just my .02

What is a "solid" number HP-wise for a stock auto or a stock 6 speed? Trying to decide which to go with.

Actually, it may be better to be asking what is the max rear wheel torque (vs max HP) before risking damage to the transmission.

The following is in regard to the Allison.

I recently posted a thread trying to find out what the rear wheel torque is on a stock LB7 and a stock LLY. Based on the responses, it seems to be about 440 ft lbs for the LB7 and about 500 ft lbs for the LLY.

The Edge web site has the following statement. "When the torque converter clutch is engaged, fifth gear on the Allison 1000 transmission will hold about 680 foot pounds of torque before slipping." Per a conversation with their Tech Support, this is 680 ft lbs measured at the rear wheels.

I believe the recent thread referenced by Solly is this one:

http://dieselplace.com/forum/showthread.php?t=24859&page=3&pp=10

The point being made in that thread is to not exceed 50 HP in an LLY or 80 HP in a LB7, and do not exceed 100 ft lbs of torque in a LLY or 160 ft lbs of torque in a LB7 if you want the Allison to have a long life. I am basing this on the comments made by Diesel Tech of TTS. Unfortunately, I did not ask him what he was getting for stock torque numbers at the rear wheels, but I will assume it is similar to the 440 and 500 numbers. Adding 440 + 160 gives 600 ft lbs max torque for the LB7 and adding 500 + 100 gives 600 ft lbs max torque for the LLY.

So, how much torque can an Allison take before shorting the life? It depends. If you exceed 680 ft lbs, it will slip (according to Edge) and this will kill it in short order. Also, if you exceed 600 ft lbs, then there is a good possibility that damage is occurring to the point of shortening the life of the transmission.

I'm aware of at least three things that impact the life of the transmission when adding power:
- How extreme one drives the truck.
- Vehicle and tow weight.
- Individual definition of acceptable transmission life.

Every time you drive the truck, the transmission is wearing out and getting closer to failure. Adding power can accelerate the wear to some degree. It is an individual decision to find that balance of additional power and acceptable wear. It appears to be somewhere between 600 ft lbs and 680 ft lbs of torque, depending on driving habits, total weight, and how long you want the transmission to last.

As a side comment, the Edge Juice does make it more difficult for me to determine what is a safe number. They offer an option to defuel between shifts. So does this mean you can run an Edge Juice at a higher torque setting than say a Predator, which does not defuel, and still get the same transmission life?

Round of applause for you!!! Thanks for breaking that down for the newbies!:horsey: Yee Haw ponies here i come... j/k

As a side comment, the Edge Juice does make it more difficult for me to determine what is a safe number. They offer an option to defuel between shifts. So does this mean you can run an Edge Juice at a higher torque setting than say a Predator, which does not defuel, and still get the same transmission life?
Are you sure the Predator doesn't de-fuel between shifts? I believe the Duramax in stock form de-fuels between shifts. I also believe the Edge will allow you to turn that off so it doesn't de-fuel, however the Predator does not allow you to alter that. Which would mean a Predator tuned Duramax will de-fuel between shifts. This is all info I have gethered from hours or researching and reading, so I'm not 100% positive, so..........
Chime in experts!

Are you sure the Predator doesn't de-fuel between shifts? I believe the Duramax in stock form de-fuels between shifts. I also believe the Edge will allow you to turn that off so it doesn't de-fuel, however the Predator does not allow you to alter that. Which would mean a Predator tuned Duramax will de-fuel between shifts.

Based on what I've read on the DiabloSport web site and from other postings on this site, I believe the Predator does not defuel between shifts. They make no claim of this function in their marketing publications. Here is a comment from the Predator website FAQ section:

"The Predator for Duramax truck has no transmission function in it at all. No manufacturers can communicate directly with the Allison transmission. It is a self-learning system, the trick is to drive it, and it will adjust to the power level your using in time."

In regard to the truck defueling in stock form, here is what Allison says in their FAQ section:

"The transmission controls have been highly integrated with the LB7 and LLY Duramax diesels and L18 gas engines in GM pickups. Part of this integration is that the TCM has a 'map' of each engine's torque output throughout its operating RPM. The TCM uses 'Shift Energy Management' (SEM). During most range shifts, there is more power available than necessary to maintain acceleration. The unused engine power traditionally goes into slipping clutches, and results in additional heat without adding to vehicle performance. Through engine/transmission communication, SEM is the electronic control process that reduces torque during range upshifts to a level resulting in consistent transmission output torque before and after the shift. The net result is optimized shift quality as well as reduced clutch energy."

"Needless to say, when engine torque is increased significantly via various after-market methods, these features are greatly compromised. As with any mechanical system, there is a limit to the level of torque/power that the transmission can handle. Pumping excessive amounts of torque into the transmission will result in excessive heat, gear and bearing loads, and clutch energy absorption."

Now, here is what Edge has to say about defueling and shifting:

"The Juice also limits the amount of power increase during transmission shifts when the torque converter clutch is engaged and also when the torque converter clutch is being engaged. This allows the torque converter clutch to engage without slippage causing “limp mode”."

My interpretation of all of this is that the Juice, when the defuel option is set to "yes", only backs off any additional power that it is producing just before the time of the shift. This reduction would be in addition to any power reductions being negotiated between the stock ECM and TCM at the same time. On the other hand, the Predator will continue to add the selected level of power, even though the stock ECM and TCM are reducing power.

If this is true, then it appears that the Predator will carry more power through the shift than the Juice. This makes me think that the Juice can be set at a somewhat higher power level than Predator like products, without increasing the risk of transmission wear. This is just speculation on my part. Like you, I am also trying to get a better understanding of how all of this works.

There is no rule of thumb as to how much power a stock Ally will hold. How the torque converter was assembled has a lot to do with it. I have seen failures on stock Allys and have seen some hold 120 hp for a while. The C3s will burn no matter what. Most stock converter clutches only grab 1/3 of the lining with the other 2/3 never touching apply service. The stronger the apply and hold on the converter clutch the better the rest of the trans will hold.
mike

I believe it is the ECM (engine control module) causing (controlling) the de-fueling, not the TCM. The Predator shouldn't effect that at all. The Edge has the ability to "turn off" the de-fueling, as opposed to "adding" this feature. I think that is how it is, Factory Techs, chime in please.

The stock ECM programing will defuel a bit. The edge will follow with the factory programing. Even with the defuling turned off via the edge there is still some defuling taking place. With defuleing on the edge pulls out more so there is just more defueling. I would recomend defuling turned on in all gears on a stock trans though. Thats one anoying thing about the edge on built trans, its defuling a bit regardless of its setting.